Re: [TLS] draft-ietf-tls-tls13-26 is vulnerable to externally set PSK identity enumeration

Benjamin Kaduk <kaduk@mit.edu> Mon, 19 March 2018 22:53 UTC

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Date: Mon, 19 Mar 2018 17:53:16 -0500
From: Benjamin Kaduk <kaduk@mit.edu>
To: Hubert Kario <hkario@redhat.com>
Cc: Eric Rescorla <ekr@rtfm.com>, tls-chairs <tls-chairs@ietf.org>, TLS WG <tls@ietf.org>, The IESG <iesg@ietf.org>
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Subject: Re: [TLS] draft-ietf-tls-tls13-26 is vulnerable to externally set PSK identity enumeration
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On Mon, Mar 19, 2018 at 05:00:51PM +0100, Hubert Kario wrote:
> On Sunday, 18 March 2018 16:27:34 CET Eric Rescorla wrote:
> > After discussion with the chairs and the AD, I have opted to just add a
> > section
> > that explains the attack. I just merged that (but managed not to get it
> > into -27
> > due to fumble fingering).
> 
> If there is no consensus on the recommended fix for the issue, I wonder if we 
> shouldn't then soften the language in the section about PSK binder handling, 
> from SHOULD to MAY.

I think on the balance I am happier retaining SHOULD.

> Though, I'd say that the reference to that newly added section is definitely 
> missing.

I expect that can be done as an RFC Editor note or during AUTH48.

-Benjamin